RE: [PATCH v3] ethdev: deprecate header fields and metadata flow actions

[Slava Ovsiienko <viacheslavo@nvidia.com>]

Hi, Ori

> -----Original Message-----
> From: Ori Kam <orika@nvidia.com>
> Sent: Wednesday, November 24, 2021 18:21
> To: Slava Ovsiienko <viacheslavo@nvidia.com>; dev@dpdk.org
> Cc: ferruh.yigit@intel.com; NBU-Contact-Thomas Monjalon (EXTERNAL)
> <thomas@monjalon.net>
> Subject: RE: [PATCH v3] ethdev: deprecate header fields and metadata flow
> actions
> 
> Hi Slava,
> 
> > -----Original Message-----
> > From: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
> > Sent: Wednesday, November 24, 2021 5:38 PM
> > To: dev@dpdk.org
> > Cc: ferruh.yigit@intel.com; NBU-Contact-Thomas Monjalon (EXTERNAL)
> > <thomas@monjalon.net>
> > Subject: [PATCH v3] ethdev: deprecate header fields and metadata flow
> > actions
> >
[..snip..]

> >
> >  Action: ``OF_SET_MPLS_TTL``
> >  ^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > +This action is deprecated. Consider `Action: MODIFY_FIELD`_.
> >
> 
> Since no PMD support this action why set reference to MODIFY_FIELD_?
> Same for all unsupported actions.

There are some references to this action in PMDs (for example bnxt),
but the ENOTSUP returned. I.e., action is in source code, but actually
not supported. Hence (due to this and in general), we can't just occasionally
remove existing actions, we should deprecate these ones first.
Other point - if someone will decide to implement support for this
action in his/her PMD - the deprecation notice will point out the right way -
"consider MODIFY_FIELD."

> 
> >  Implements ``OFPAT_SET_MPLS_TTL`` ("MPLS TTL") as defined by the
> > `OpenFlow  Switch Specification`_.
> > @@ -2254,6 +2255,7 @@ Switch Specification`_.
> >
[..snip..]
> 
> If no PMD support this why do we want to add it to the modify_field?
> Same for all of the unsupported actions.
As I said above - we just propose to consider MODIFY_FIELD actions
if someone has intention to implement deprecated OFPAT_SET_MPLS_TTL.

[..snip..]

> >   *
> > --
> > 2.18.1
> 
> Best,
> Ori

With best regards,
Slava